Researchers with the Nippon Telegraph and Telephone Corporation (NTT) and the Hokkaido National University Organization Kitami Institute of Technology have succeeded in breaking the record for the longest-distance power delivery through a single fiber optics cable. Previously only achieved for a distance up to two kilometers (due to optical intensity limits within the fiber itself), the results open up venues for disaster relief/recovery and power delivery in remote locations without the need for complex electrical infrastructure to be built (or rebuilt). The researchers managed to deliver in excess of 1 W (in addition to the high-speed data exchange allowed by fiber optics) across a 10km distance.
The feat makes use of NTT's multicore optical fiber (MCF) — a technology that keeps compatibility with existing fiber optics infrastructure through its standard glass diameter of 125 μm. But due to it being multi-core (meaning that there are a number of individual optical strands within the standard glass), each of these cores can be leveraged for their own purpose. In order to maximize power delivery, however, using multiple cores for power transmission may be required.
That's exactly what the research team did, however. The scientists pushed a light source with a wavelength of 1,550 nm into all four optical cores. For data transmission, two of the cores were injected with an additional wavelength around 1,310 nm, where both downlink and uplink data (with a transmission speed of 10 Gbps) could piggyback on. In the end, the researchers managed to send approximately 1 W of power across a 14 kilometer distance, achieving a world-record 14 W/km for their optical power supply system.
There's been a number of advances in photonics technology in the last few years, and this particular research now enables long-range energy delivery while also enabling wired communications. It's an incredibly simple and cost-effective solution for low-power delivery across distances and lacking electrical infrastructure, and one that's sure to see applications in the future.